Typewriting machine



Nov. 15,1932. w. F. HELMOND 1,888,035

TYPEWRITING MACHINE Filed July 25, 1929 Patented Nov. 15, 1932 i UNITED STATES PATENT mar;

WILLIAM F. HELMOND, 01 WEST HARTFORD, CONNECTICUT, AssIenon To onnnnwoon ELLIOTT FISHER COMPANY, or new YORK,1\T. Y., A CORPORATION or DELAWARE z T TYPEWRITING MACHINE Application filed July 25,

This invention relates to means for effecting the line-feeding of the paper in typewriting machineshaving revoluble platens, and particularly machines having platen-mechanisms of the Underwood type.

In the Underwood machine the platen is rotated. by means of a lever which returns the carriage to begin a new line. This lever drives a plunger or slide, upon which is 1 pivoteda pawl which is'caused to engage a ratchet-wheel that is secured to the platenaxle, thereby rotating the platen.

Since the typewriter-carriage must be started and stopped at extremely short intervals, it is necessary for the carriage and allparts to, be light. This tends to weakness; and it is one of the problems of typewriter-construction to produce a line-spacing mechanism of sufficiently light construction in such a manner as to have no faulty action due to weakness. One of the faults of ordinary construction is that the heavy platen, which is rotated very suddenly, is apt to overthrow and thus produce irregular line-spacing of the work-sheet. This overthrowing is due in part to the necessity of using light parts, but it is one of the objects of the pres ent improvement to overcome the objection I without sacrificing lightness.

Another common fault is that there is rapid wear of the parts, especially the plunger, so that it becomes loose in its guides and tends to produce faulty line-feeding of the platen.

The platen-driving pawl in the Underwood machine is pivoted on one side of the plunger which is in the nature ofa' horizontal blade extending rearwardly on edge. This blade is light, and when the drive-pawl is sharply arrested the momentum of the operaf tors hand tends to spring the blade, or to twist it, and this yieldingof the parts is another source of faulty line-feeding of' the work-sheet.

Said line-spaceplunger is mounted in one of the ends of the shiftable platen-frame,

which comprises two ends of light construction, and a connecting bar. The left-hand end is usually formed with front and rear bearings for the line-space plunger. The

.50 front bearing is usually provided by bending 1929. Serial No. 380,872.

down an ear which is formed upon the front of the frame-end, and cutting a guide-slot near the bottom of the ear for guiding the plunger. Provision is also usually made for guiding the plunger at its rear end.

According to the present improvements, said front guide-slot of the line-space plunger is supplanted by means of a novel bracket having a vertical plate-portion which is attached to the platen-frame end, and also hav- 9 ing a flange or ear bent out therefrom and formed with a rectangular guiding eye. This bracket is mounted at the front of the platen- 7 frame end, and said eye is offset considerably from the body ofthe plunger, but the latter is prgf' led with a forward extension which is bent feflexly forming a U, the end of the U beinginserted in said guiding eye and fitting the same closely, and serving the function of front guiding means for the plunger.. The guide-bracket is of hardened steel, and not open to theobjection of wearing away,

; so that looseness does not occur.

The body of the plunger usually" works in a slide-way, of which the top portion consists of an upper flange or table that is formed upon the platen-frame end; and the bottom and side portions consist of a rear slotted bracket in which the plunger is fitted- The novel bearing at the side is sufficiently separated from the body of the plunger to give a broad support, which precludes any twisting or rocking action of the plunger when violently operated, so that trouble from overthrow of the platen is minimized or ielimi nated. v V

The line-space lever engages the bent end of the plunger, which afiords a broadengaging surface that is not liable to faulty operation, while the pressure of the lever end is mainly applied at points between the left hand and right-hand bearings of the plunger, so as to'conduce to ease of action. The fault of liability of binding of the plunger is overcome by the present improvements.

To maintain the platen against rotation during thejtyping of the line, there is usually provided a detent-arm that is mounted upon the platen-frame and carries at its end a roll which rides in thenotches of the linespace 100 notches are spaced closely together, in order bodily.

to afford closeness of spacing of the typed lines; and it is one of the features of this invention that the sensitive action of this rollerdetent is substantially improved, and accuracy of movement of the platen is secured, even when the teeth have small pitch.

Said line-space wheelis usually pinned to the platen-axle, and is usually with-drawn therewith preparatory to dismounting the platen. According to the present improvements, a collar is driven upon the axle to be dismounted therewith. and a ball-race is mounted upon said collar, and balls placed therein; this ball-bearing and the axle and the line-space wheel forming a unit which can be taken out of the machine and replaced This ball-bearing is so close alongside of the line-space wheel that the pressure of the spring may be greatly increased, which presses the detent-roller into the notches of the line-space wheel, thereby increasing the efiiciency of the line-space detentand improving the accuracy of the line-feeding of the paper. This is accomplished without making it more diflicult to rotate the platen by means of the usual finger-wheels placed upon the ends of the axle. The right-handend f the platen-axleturns in a plain bearing, and the axle is drawn to the left when disassembling.

Other features and advantages will hereinafter appear.

In the accompanying drawing,

Figure 1 is a perspective view, partlv in section, of the line-spacing end of a standard Underwood typewriting machine.

Figure 2 is a perspective of the front portion of the left-hand end of the platen-frame.

Figure 3 shows the overthrow stop for the platen.

Figure 4 is a front sectional elevation of he platen-frame, showing the parts separated.

Figure 5 is a perspective view, partly in section, giving details of the line-space slide and bearings.

Figure 6 is a sectional front elevation of platen-frame, slide and ball-bearing.

Figure 7 is a perspective of a novel guidebracket.

A line-space lever 10 is pivoted to the main carriage 12 at 13. It is in the form of a bell-crank having an arm 14 engaging the front end of a slide 15, which is substantially U-shaped having a leg 16. The arm 14 engages the bottom 18 of the U-shap-ed portion of the slide 15.

The slide is supported and guided in a shift-frame 19 of the platen 20 in a guide 21 at the rear of the machine and guides 22. 23 and 23 at the front of the machine. The rear guides 21 and 23 and 23 are formed on the shift-frame 19, while the front guide 22 is a separate bracket bent in substantially L-shape with a guide-slot 24 cut in the base of the L, this bracket being hardened steel. It is secured to the shift-frame by rivets 25. The slot 24 is of a size to fit the end 16 of the U-shaped portion of the slide 15 to guide it both vertically and horizontally without binding.

The main body of the slide 15 is made to fit in a vertical direction in the opening 26, in which the top and bottom edges form the guides 23 and 23 in the front end of the shiftframe 19. It will thus be seen that the wear is almost entirely on the guide 22 as the guides 23 and 23 counteract any tendency to twist or rotate. By this means the slide is held so as to reciprocate back and'forth during operation without binding, and yet without an undue amount of play, therefore mak ing it practically noiseless and reliable.

The rear end of the slide 15 has a pin 27 to which is attached a return spring 28, the other end of which is secured to the shiftframe 19. The cost of manufacture is not increased to any appreciable degree because this extra bearing is verysrnall and a simple part which is inexpensive to make and yet efiective in its operation. 7

The slide 15 has pivoted to it an arm 29 withdetent-pawl 30 to'engage the teeth of 'a ratchet-wheel 31 mounted on a shaft 32 of the platen 20. This arm 29 reciprocates freely with the leg 17 of the slide through the opening'26 in the shift-frame.

Attached to the platen-shaft is a-handwheel 33 for hand-operation of the spacing device. In order to hold the platen securely in position after the line-space is made, a

' detent 34, pivoted on a screw 35 fastened to the shift-frame 19, is provided. The detent has a roller 36 pivoted to its forward end and a strong coil-spring 37 holds the detent in engagement with the teeth of the ratchetwheel 31. The-usual regulation is employed for engaging the pawl 30 with the ratchetwheel 31 to produce either one or two linespaces, which is not shown, but is disclosed in the patent to Alfred G. F. Kurowski, N0. 1,190.658, dated July 11, 1916.

It has been found that on account of the of these parts would produce considerable" play, which caused faulty action and required early replacement of the parts. In order to overcome this tendency and to render the platen-detent eficient, a sleeve or collar 38 is put on the shaft with a driving fit. This sleeve has a flange 39 against which a ring 40 is held to form one side of a race for balLbearing's 41, and another ring 42, which is a duplicate of 40, is used to form the other .part of the inner raceway for the balls 41.

An outer raceway or groove for the same balls is made in an outer bearing 43 which is secured to the shift-frame 19 by screws 44. This bearing is assembled on the sleeve 38 after which a slight swedging on the end of the sleeve 38 will flare it out, as shown at 38*, thus holding the bearing on the sleeve securely. Openings 46 in the ratchet-wheel 31 permit access to the screws 44 in order to fasten the bearing 43 to the shift-frame. The platen 20 is held on the shaft 32' by means of a set-screw 47. The ratchet-wheel 31 is secured to the shaft 32 by means of a pin 48 driven through a hole in a collar 49 of the ratchet-wheel and the shaft 32.

The parts are readily assembled as follows: The ratchet-wheel 31 is placed on the shaft 32 and the pin 48 is driven into the collar 49 and shaft 32. The sleeve 38 is then driven onto the shaft. The bearing-collar 40 is then slidden in position over the sleeve 38. The outer bearing 43 is next put in place and the rollers 41 put in the race. After this, the bearing-collar 42 is slidden to place over the sleeve 38 and the end of the sleeve is swedged in place as described. This assembles the entire ball-bearing and holds it on the shaft 32 of the platen. The shaft 32, with its bearing and ratchet-wheel attached, is

slidden through the platen 20 and its bearing at the opposite end, and secured in place by the screws 44, through the outer part of the bearing 43 and in the platen-frame 19. The hand-wheel 33 is then put on the end of the shaft and secured to the same by the setscrew 45.

The guiding notch 21 is formed in the usual bracket 50, secured to the left-hand side of the platen-frame end 19. This bracket 50 is formed with an angular projecting plate 51 in which said notch 21 is formed. On said plate there is also formed a pendent stop 52, which intercepts the nose 53 of the pawl 29, to lock the line-space wheel and platen against overthrow, Figures 1 and 3.

paper-carriage, a revoluble platen, a ratchetwheel therefor, a line-space lever mounted upon the carriage, and a shiftable platenframe mounted upon said carriage, the combination of a front guiding eye in the form of a bracket of hardened metal fastened upon the end of said platen-frame, and a line-space slide engaged at its front end by said lever and having a pawl to drive said ratchetwheel and having a reflex bend at its front end terminating in an integral guide-tongue guided solely in said front eye, and a single rear lateral guide for said slide, having means for retaining the slide in said rear guide.

3. In a typewrit-ing machine having a paper-carriage, a revoluble platen, a ratchetwheel therefor, a line-space lever mounted upon the carriage, and a shiftable platenframe mounted upon said carriage, the com bination of a front guiding eye in the form of a bracket of hardened metal fastened upon the end of said platen-frame, and a line-space slide engaged at its front end by said lever and having a pawl to drive said ratchet-wheel and having a reflex bend at its front end terminating in an integral guide-tongue guided solely in said front eye, said platen-frame having a front slide-way engaging only the top and bottom edges of the slide, and said reflex bent end being substantially offset from the slide to give the same a broad bearing, and a single rear lateral guide for said'slide, havingneans forretaining the slide in said rear gul e. v

- WILLIAM F. HELMOND.

Variations may be resorted to within the 1 scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine having a paper-carriage, a revoluble platen, a ratchetwheel therefor, a line-space lever mounted upon the carriage, and a shiftable platenframe mounted upon said carriage, the combination of a front guiding eye in the form of a bracket of hardened metal fastened upon the front of the end of said platen-frame, and a line-space slide having a pawl to drive said ratchet-wheel and having a reflex bend at its front end terminating in a front slide-guiding tongue guided in said eye, said platenframe having rear means for laterally guiding the rear of the line-space slide.

2. In a typewriting machine having a 

